#micelles

Germ cells are surrounded by a cell wall that protects them from the environment. This cell wall is made up of a layer of peptidoglycan, which is a polymer of amino acids and sugars. Soap molecules are made up of two parts: a hydrophobic (water-fearing) tail and a hydrophilic (water-loving) head. When soap is added to water, the hydrophobic tails group together and the hydrophilic heads face outward, forming micelles. These micelles can surround germ cells and the hydrophobic tails can then disrupt the cell walls, causing the cells to burst.

The hydrophobic tails of the soap molecules can disrupt the cell wall in two ways. First, they can bind to the peptidoglycan molecules and weaken the bonds between them. Second, they can create holes in the cell wall. Once the cell wall is disrupted, the germ cells lose their internal contents and die.

It is important to note that soap only works to kill germ cells that are surrounded by a cell wall. Germ cells that do not have a cell wall, such as viruses, are not affected by soap.

The size of the soap micelles is important. Micelles that are too small will not be able to surround the germ cells. Micelles that are too large will not be able to penetrate the cell walls.

The concentration of soap is also important. A higher concentration of soap will be more effective at killing germ cells.

The temperature of the water can also affect the effectiveness of soap. Soap is more effective at killing germ cells in warm water than in cold water.

I hope this post has helped you understand the importance of handwashing and why doctors always ask you to do it regularly. Washing your hands with soap and water for at least 20 seconds is one of the best ways to prevent the spread of germs and stay healthy. So please, wash your hands often and help keep yourself and others safe!

Engineering team images tiny quasicrystals as they form

When Israeli scientist Daniel Shechtman first saw a quasicrystal through his microscope in 1982, he reportedly thought to himself, "Eyn chaya kazo" -- Hebrew for, "There can be no such creature."

But there is, and the quasicrystal has become a subject of much research in the 35 years since Shechtman's Nobel Prize-winning discovery. What makes quasicrystals so interesting? Their unusual structure: Atoms in quasicrystals are arranged in an orderly but nonperiodic way, unlike most crystals, which are made up of a three-dimensional, orderly and periodic (repeating) arrangement of atoms.

The lab of Uli Wiesner, the Spencer T. Olin Professor of Engineering in the Department of Materials Science and Engineering (MSE) at Cornell University, has joined scientists pursuing this relatively new area of study. And much like Shechtman, who discovered quasicrystals while studying diffraction patterns of aluminum-manganese crystals, Wiesner came upon quasicrystals a bit by accident.

While working with silica nanoparticles -- from which the Wiesner lab's patented Cornell dots (or C dots) are made -- one of his students stumbled upon an unusual non-periodic but ordered silica structure, directed by chemically induced self-assembly of groups of molecules, or micelles.

The Scientific Research Notes Of S. Sunkavally (years: 2002-2011).

(via COVID-Causing Virus in Air Detected with High-Tech Bubbles | PNNL)

A team of scientists at the Department of Energy’s Pacific Northwest National Laboratory created a new kind of micelle, one that is stamped on the surface with copies of an imprinted particle for SARS-CoV-2.

The team filled micelles with a salt capable of creating an electronic signal but that is quiescent when packed inside a micelle. When a viral particle interacts with one of the imprinted receptors on the surface, the micelle pops open, spilling the salt and sending out an electronic signal instantly.

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The team estimates that the technology can pluck one viral particle out of billions of other particles. The detector is so sensitive that the team had a challenging time identifying the lower limit. The team used both inactivated SARS-CoV-2 viral particles and the virus’s spike protein in its tests.

Micellar foam films show grayscale intensity variations that correspond to rich nanoscopic topography mapped using IDIOM protocols. (Image: Chrystian Ochoa & Vivek Sharma/UIC)

Researchers discover foam ‘fizzics’

Chemical engineers at the University of Illinois Chicago and UCLA have answered long-standing questions about the underlying processes that determine the life cycle of liquid foams. The breakthrough could help improve the commercial production and application of foams in a broad range of industries.

Findings of the research are featured this month in Proceedings of the National Academy of Sciences.

Foams are a familiar phenomenon in everyday lives — mixing soaps and detergents into water when doing dishes, blowing bubbles out of soapy water toys, sipping the foam off a latte or milkshake. Liquid foams can occur in a variety of natural and artificial settings. While some foams are produced naturally, as in bodies of water creating large ocean blooms on the beaches, others arise in industrial processes. In oil recovery and fermentation, for example, foams are a byproduct.  

Whenever soapy water is agitated, foams are formed. They are mostly gas pockets separated by thin liquid films that often contain tiny molecular aggregates called micelles. Oily dirt, for example, is washed away by hiding in the water-phobic cores of micelles. In addition, fat digestion in our bodies relies on the role of micelles formed by bile salts.

Over time, foams dissipate as liquid within the thin films is squeezed out. Soap and detergent molecules that are by very nature amphiphilic — both hydrophilic and hydrophobic — aggregate within water to form spherical micelles, with their outward-facing heads being hydrophilic and water-phobic tails forming the core.

“Micelles are tiny, but influential, not just in cleaning and solubilizing oil-loving molecules but also in affecting flows within foam films,” said co-principal investigator Vivek Sharma, an associate professor of chemical engineering at the UIC College of Engineering. For nearly a decade, he has pursued the question of how and why the presence of micelles leads to stepwise thinning, or stratification, within ultrathin foam films and soap bubbles.

To solve the puzzle, Sharma and his collaborators developed advanced imaging methods they call IDIOM (interferometry digital imaging optical microscopy) protocols that are implemented with high speed and digital single-lens reflex, or DLSR, cameras. They found that foam films have a rich, ever-changing topography, and the thickness differences between different strata are much greater than the size of micelles.

“We used a precision technique called small-angle X-ray scattering to resolve the micelles’ shape, sizes, and densities,” said co-principal investigator Samanvaya Srivastava, an assistant professor of chemical and biomolecular engineering at the UCLA Samueli School of Engineering. “We found that the foam film thickness decreases in discrete jumps, with each jump corresponding to the exact distance between the micelles in the liquid film.”

The team also discovered that the arrangement of micelles in foam films is governed primarily by the ionic interactions between micelles. The electrostatic attraction and repulsion between ions influences how long foams remain stable and how their structure decays. With these findings, the researchers determined that by simply measuring the foam film thickness, which can be accomplished with a DSLR camera using the IDIOM protocols, they could characterize both the nanoscale interactions of micelles in liquids and the stability of the foams.

Compared with previous techniques that are more time-consuming and require expensive, customized equipment, the new method is not only less expensive but is also more comprehensive and efficient.

“The knowledge and understanding could aid in the development of new products — from food and personal care to pharmaceuticals,” said the study’s co-lead authors, graduate students Shang Gao of UCLA and Chrystian Ochoa of UIC. “It could also help engineers improve the control of foams in industrial processes.”

Why is Milk White? https://ift.tt/2JFWCcC Milk is mostly made up of water, with smaller amounts of fat, protein, minerals, and other compounds. Fats and water don’t usually mix, but in milk the fat and water form an emulsion. It is also a suspension of a multitude of different proteins in water.

The Chemistry of Milk - Click here for more.

In milk, proteins cluster together to form structures called micelles. These clusters grow from small clusters of calcium phosphate, which help hold them together. There are a number of different models of these micelles, with the exact structure still being subject to scrutiny.

  It’s the protein micelles which give milk its white appearance. The micelles are on average about 150 nanometres in diameter, and this very small size means they are able to scatter light that hits them. The overall effect of this scattering by the huge number of micelles in milk is that it looks white.

For a fuller explanation and for more information please visit:-

Nanomedicine Targets Gastric Tumors

Prof. Yehuda Assaraf, Dean of the Faculty of Biology and Director of the Fred Wyszkowski Cancer Research Laboratory

A study conducted at the Technion, and published in the journal Oncotarget introduces innovative technology for future treatment of stomach cancer. The new treatment modality is based on a transport platform developed at the Technion using a combination of anti-cancer drugs and a…